Antimony-activated calcium halophosphate containing boron

ABSTRACT

RELATES TO ALKALINE EARTH HALOBORAPATITE PHOSPHORS ACTIVATED WITH ANTIMONY AND USEFUL IN FLUORESCENT LAMPS AND OTHER APPLICATIONS.

April 25, 1972 s. JONES 3,658,715

ANTIMONY-ACTIVATED CALCIUM HALOPHOSPHATE CONTAINING BORON Filed Jan. 26,1970 Fig. 3.

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EELHT/VE ENERGY 2 Sheets-Sheet 2 2o 5 g 15 E g 4110 9060? E g 5CHLOEOBOEHPHT/ 5 2 5 EXCITING Wm/EL ENGTH (mm) fxc/mr/o/v SPfcr/efl FLUOBOP T/ f 5 WAVELENGTH (nm) SPECTEHL DISTRIBUTIONS UNDER 253. 7 nmfxc/mTmN Q 40 u E 20 I I i,

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WAVELENGTH (nm) I t SPECTEHL D/5TP/BUT/0NS UNDfE' T7VT7 T.

Shannon defies His Ark-horne 253'. 7 nm [Xe/m T/0N United States PatentO 3,658,715 ANTIMONY-ACTIVATED CALCIUM HALO- PHOSPHATE CONTAINING BORONShannon Jones, South Euclid, Ohio, assignor to General Electric CompanyFiled Jan. 26, 1970, Ser. No. 5,678 Int. Cl. C09k 1/36 US. Cl. 252301.4P 20 Claims ABSTRACT OF THE DISCLOSURE Relates to alkaline earthhaloborapatite phosphors activated with antimony and useful influorescent lamps and other applications.

BACKGROUND OF THE INVENTION This invention relates generally tophosphors and more particularly to calcium haloborapatite phosphorshaving broad spectral emission peaks.

The alkaline earth halophosphate phosphors are well known. Thesephosphors are useful as luminescent materials when activated. A typicalantimony-activated phosphor of this type may be written:

3Ca3 CaX I where X is one or more of the halogens fluorine and chlorine.

In general, the halophosphates are compounds more or less analogous tothem ineral aptite, which may be represented by the matrix:

where X represents a halogen or a mixture of halogens and M and Mrepresent either different or identical bivalent metals or mixtures ofsuch metals.

The primary metallic constituent for most halo-phosphate phosphors iscalcium although strontium can be used to replace part or all of thecalcium. The halide constituent prior to firing normally comprisescalcium or strontium chlorides or fluorides or mixtures of both and thematrix is normally activated by antimony or antimony plus manganese.

In the present invention the antimony-activated phosphor (l) 3Ca (P-0.9CaX -0.1SbOX has been modified, for example, as follows:

(2) 3Ca (PO 0.9BOX-0.lSbOX X=halogen.

In both Formulas 1 and 2 Sb is trivalent, and the substitution of oxygenfor one of the halogens in part of the CaX provides charge compensation.When the remainder of the CaX is replaced by ROX, where R is trivalent,unusual results were obtained. The trivalent elements tried included B,Al, Y, La, Ga and In. However, of the tnvalent elements tried, onlyboron gave a substantial visual color variation, e.g., changing thecolor from blue-white to white under ultraviolet (UV) 253.7 nanometer(nm.) excitation. This property of boron was unexpected because of itssmall ionic size. Furthermore, it was found that CaO in excess of theequivalent in Formula 2, gave brighter white phosphors. Such a formula,e.g., is

(3) 3Ca (PO -0.9BOX-0.1SbOX-0.5Ca0

X=halogen.

SUMMARY OF THE INVENTION It is therefore an object of my invention toprovide a luminescent material activated with antimony or antimony plusmanganese and containing trivalent boron.

3,658,715 Patented Apr. 25, 1972 wherein M is wholly or predominantlycalcium although partial substitution of minor amounts such as up toabout 2.5 to 5 atom percent of Sr. Ba or Cd can be tolerated, and X isfluorine or chlorine, and wherein x has a value of from 8.85 to 9.35, yhas a value of from 0.25 to 0.55, w has a value of from 0.05 to 0.5, and2 has a value of from 0.15 to 0.65. An example of this phosphorexpressed in other terminology is:

As stated, some partial substitution for calcium by strontium, barium orcadminum (which is not an alkaline earth metal) does not substantiallyaffect the brightness or color of the calcium fluoroborapatite2Sb. Forexample, in the formula:

3Ca (PO9 0.8BOF- 0.2SbOF 0.25CaO- 0.25RO' R may be strontium, barium orcadmium with very little effect on brightness or color.

It should be noted that, while in the borapatite phosphor antimony isthe essential activator, its concentration is not critical.

Those parts of the present invention which are considered to be new areset forth in detail in the claims appended hereto. The invention,however, may be better understood and further objects and advantagesthereof appreciated from a consideration of the drawings and detaileddescription.

DRAWINGS AND DETAILED DESCRIPTION FIG. 1 is a spectral distributiongraph with constant 253.7 nm. excitation showing the relativelybrightness of specific phosphors.

FIG. 2 is a spectral distribution graph normalized to peak at 60 units,comparing the emission spectra and peaks of specific phosphors. Theincreased emission of the borapatites in the red (600 to 700 nm.) isevident in this figure.

FIG. 3 is a graph of the excitation spectra of fluoroborapatite andchloroborapatite relative to sodium salicylate.

FIG. 4 shows the emission of a fluoroborapatite in the infrared.

FIG. 5 compares the emission of a fluoroborapatite of the invention withcalcium haloapatite activated with antimony, and with MgWO both beingphosphors of the prior art.

Referring more particularly to FIG. 1, fluoroborapatite compositions 17and 11 of Test II are compared to chloroborapatite composition 26 under253.7 nm. excitation. The tests demonstrated that composition 17 of TestII, which had the high CaF low H BO and low CaCO was the brightest being42.9% of NT, (cool-White calcium fluorchlorapatiterSb, Mn) as furthershown in Photometric Data of Table II referred to hereinafter. However,the spread in UV absorption, brightness and color was considerably lessover the compositions in Test H than in Test I.

Referring more particularly to FIG. 2, the compositions 17 and 11 ofTest II, using magnesium tungstate N.B.S. 1027 (BW) as a standard, arecompared for color. The results are cataloged in Photometric Data ofTable II referred to hereinafter. The results may be compared with 5Photometric Data of Test I in Table I as well as Photometric Data ofTables III and IV referred to hereinafter. All the tests 'were conductedunder 254 nm. excitation. The color coordinates x and y are those of theOLE. International system, as described by Deane B. Judd in Color inBusiness, Science and Industry, pages 99, 101 et seq., Wiley, 1952. Thesubjective colors depend on the surrounding colors but for all thephosphors they are pastels or off-whites with a broad-band spectralemission. As an example, composition 8 in Photometric Data of Table Iwas blue-white whereas composition 2 of the same table was ayellow-pink-white composition. Chloroborapatite, number 26, on the otherhand, was yellow-white or yellow-green-white. All the phosphors referredto are useful because of their flat distribution of light output.Referring to FIG. 3, there is shown a graph depicting a composition offluoroborapatite number 11 and chloroborapatite number 20 relative tosodium salicylate as a standard, when excited by different wavelengths.

Further, FIG. 4 shows the emission of the fluoroborapatite composition,number 17 of Test II hereinafter,

into the infrared region (700 to 900 nm.), and

FIG. 5 shows the fluoroborapatite composition number 17 of Test II vs.regular fluorapatitezSb (BT-blue-white calcium fluorapatitezSb), as wellas magnesium tungstate. The increased red emission (600 to 700 nm.) dueto boron is evident.

A preferred embodiment for brightness comprises the composition:

8.85Ca 3P O 0.3B O 0.2SbOF- 0.65CaF However, the composition:

9.10Ca0 3P 0 0.4B O 0.2SbOF- 0.40CaF has a better color for some uses inthat it is less blue.

In preparing the compositions of this invention, the temperatures arenot critical and the phosphors may be fired over a range from about 1120C. to 1200 C. with little brightness change. The center compositionnumber 2, referred to below, has been fired as high as 1246 C. with onlya slight loss in brightness and slight color shift but when fired at1295 C., a new phase, a more saturated yellow under 253.7 nm. excitationappeared. For the chloroborapatites 1140 C. is a good temperature, 1120C. to 1160 C. a reasonable limited range while greater deviations, 1100C. or 1200 C. will begin to cause brightness loss.

Specific examples of the procedure used in the preparation of thephosphor compositions of this invention are given below. First theexamples for Test I.

EXAMPLE I Relative mols: Grams 6.00--CaHPO 828 2.75CaCO 275 (It.60H BO37 0.10Sb O 29 0.25-CaF 20 8.85CaO 31 0 0.3B 0; 0.2SbOF- 0.15CaF 4EXAMPLE 2 Relative mols: Grams 6.00CaHPO 828 3.00-CaCO 300 0.80-H5BO 500.10Sb O 29 0.50-CaF 39 The above ingredients were mixed and fired inthe same manner as in Example 1 and had the following composition,assuming no loss of Sb, F or B:

9.10CaO 3P O O.4B O 0.2SbOF 0.40CaF EXAMPLE 3 Relative mols: Grams6.00CaHPO 828 3.25CaCO 325 1.O0H BO 62 0.1o sb,,o 29 O.75CaF 59 Theabove ingredients were mixed and fired in the same manner as in Example1 and had the following composition, assuming no loss of Sb, F or B:

9.3 SCaO 3P O 0.513 0 0.2SbOF 0.65CaF EXAMPLE 4 Relative mols: Grams-6.00CaI-IPO 828 3.25CaCO 32.5 0.60H BO 37 0.10-Sb O 29 0.75-CaF, 59

The above ingredients were mixed and fired in the same manner as inExample 1 and had the following composition, assuming no loss of Sb, For B:

EXAMPLE 5 Relative mols: Grams 6.00CaHPO 828 3.2'5CaCO 325 1.0041 30, 620.10-Sb 0 29 0.25-Ca1F 20 The above ingredients were mixed and fired inthe same manner as in Example 1 and had the following composition,assuming no loss of Sb, F or B:

The above ingredients were mixed and fired in the same manner as inExample 1 and had the following composi-' tion, assuming no loss of Sb,F or B:

9.35 CaO- 3P O 0.3B O 0.2SbOF- 0.15CaF EXAMPLE 7 Relative mols: Grams6.00CaI-IPO 8-28 2.75--CaCO 275 1.0O-H BO 62 O.l0'Sb O 29 0.75CaF 59 Theabove ingredients were mixed and fired in the same manner as in Example1 and had the following composition, assuming no loss of Sb, F or B:

8.85 CaO 3P O 0.5B O 0.2SbOF- CaF 5 EXAMPLE 8 Relative mols: Grams6.00CaHPO 828 2.75-CaCO 275 0.60H BO 37 0.10-'Sb O 29 0.75-CaF 59 Theabove ingredients were mixed and fired in the same manner as in Example1 and had the following composition, assuming no loss of Sb, F or B:

8.85Ca 3P O 0.33 0 0.2SbOF- 0.65 CaF 'EXAlVIPLE 9 Relative mols: Grams6.00CaHPO 828 2.75CaCO 275 1.00H BO 62 0.10Sb O 29 0.25CaF 20 The aboveingredients were mixed and fired in the same manner as in Example 1 andhad the following composition, assuming no loss of Sb, F or B:

Of the compositions prepared above, Example 8 was visually the brightestunder 254 nm. excitation. Compared with Example 2, Example 8, wasblue-White where Example 2 was yellow-pink-white. Relative luminance andpercentage ultraviolet absorption readings as well as color measurementsin the 6.1.13. system and color impressions are as follows:

TABLE I Photometric Data for Test I 1 Standard cool-white Cafluorchlorapatlte: Sb, Mn. 9 Standard calcium fluoropatite: Sb.

The second two-level, three-factor test was run, as discussed below forTest II, around the same center composition as No. 2 in Test I. Here therange was greater for H BO and smaller for CaCO and CaF- In this secondtest the CaCO ranged from 2.88 to 3.12, the CaF from 0.36 to 0.64, the HBO from 0.50 to 1.10.

Again it was No. 17 in Test II which had the high CaF low iH BO and lowCaCO composition, that was the brightest, being 42.9% of NT.

The spread in UV absorption, brightness and color was considerably lessover the nine compositions in Test II than in Test I.

The following procedures were used in the preparation of the phosphorsof Test II:

The above ingredients were mixed and fired in the same manner as inExample 1 of Test I and had the following composition, assuming no lossof Sb, F or B:

8.98CaO 3P O 0.25B O 0.2SbOF 0.26CaF;

EXAMPLE 11 Relative mols: Grams 6. 00-CaHPO 828 3.00-CaCO 300 0.8OH BO50 0.10 sb,0 29 0.50CaF 39 The above ingredients were mixed and fired inthe same manner as in Example 1 of Test I and had the followingcomposition, assuming no loss of Sb, F or B:

9.10Ca0 3P O 0.4B O -0.2SbOF -'0.40CaF Although this is nominally thesame composition as that of Example 2 in Test I, it was prepareddifferently and had slightly different properties, as indicated below.

EXAMPLE 12 Relative mols: Grams 6.00CaHPO 828 3.l2CaCO 312 1.10H BO 68'0.10Sb203 0.64-CaF 50 The above ingredients were mixed and fired in thesame manner as in Example 1 of Test I and had the following lowingcomposition, assuming no loss of Sb, F or B:

9.22CaO 3P O 0.5513 0 -O.2'SbOF -0.54CaF EXAMPLE 13 Relative mols: Grams6.00-CaHPO 828 3.12CaCO 312 0.50H BO 31 -0.10Sb O 29 0.64CaF 50 Theabove ingredients were mixed and fired in the same manner as in Example1 of Test 1 and had the following composition, assuming no loss of Sb, For [8:

9.22CaO 3P O' 0.2513 0 -0.2SbOF- 0.54CaF EXAMPLE 14 Relative mols: Grams6.00-CaHPO 828 3.12-CaCO 312 1.10H BO 68 0.l0-Sb O 29 0.36-CaF 28 Theabove ingredients were mixed and fired in the same manner as in Example1 of Test I and had the following composition, assuming no loss of Sb, For B:

The above ingredients were mixed and fired in the same manner as inExample 1 of Test I and had the following composition, assuming no lossof Sb, F or B:

9.22CaO 3P O 0.253 0 0.2SbOF -0.26CaF EXAMPLE 16 Relative mols: Grams6.O0-CaHPO 828 2.88CaC0 288 1.10 -H,B0 68 0.l0Sb O 29 0.64CaF 50 Theabove ingredients were mixed and fired in the same manner as in Example1 of Test I and had the following composition, assuming no loss of Sb, For B:

8.9 8CaO 3P O 0.5 5B O 0.2SbOF 0.54CaF 7 EXAMPLE 17 Relative mols: Grams6.00-CaHPO; 828 2.88CaOO 288 =0.50-H BO 31 0.10Sb- O 29 0.64CaF 50 Theabove ingredients were mixed and fired in the same manner as in Example1 of Test I and had the following composition, assuming no loss of Sb, For B:

EXAMPLE 18 Relative mols: Grams 6.00-CaI-IPO 828 2.88CaCO 2-88 l.10-H BO68 0.10--Sb,0 29 0.36CaF 28 The above ingredients were mixed and firedin the same manner as in Example 1 of Test I and had the followingcomposition, assuming no loss of Sb, F or B:

8.98Ca 3P205 055E 0 0.2SbOF 0.26CaF TABLE II Photometric Data-Compartsonof Tests I and II Color UV Lumi- Example No. absorption nance x y It hasbeen found that the Sb content is relatively noncritical. This toleranceis demonstrated by a test in which the total R 0 was kept constant(including B 0 from H 30 in a formula similar to Example 2 in Test I andExample 11 in Test The only variation was in the sb,0,=B,o, ratio asfollows:

Relative mols Low Sb High Sb No. 11A No. 11B

6 6 3 a 0. 950 (0.475 0. o (0. 25 0. 025 o. 25 0. 5 0. 5

These batches were fired at l150 (3.; the photometric data follows:

TABLE III Photometric Date-Sb Variations UV Color absorption Lumi-Bample percent nanoe x y From the above data we see that No. 11 of TestII, which has an Sb:B atomic ratio of 1:4, has virtually the same UVabsorption and brightness as No. 11B, which has an Sb:B atomic ratio of1:1.

CHLOROBORAPATI'I ES In formulating the chloroborapatite phosphors,instead of substituting CaCl for CaF CaCOQ-l-NILCI is used. With NH Clit is desirable to use an excess to allow for volatilization. Thisexcess is not critical.

EXAMPLE 19 Relative mols: Grams 6.00-CaHPO; 828 2.88-CaCO 2'88 0.S0H;BOs--..-. 31

8 Relative mols: Grams 0. 10Sb O 29 0.3 6CaCl 1 36 1 cac0=+ 5s NHlc1 Theabove ingredients were mixed and fired m a crucible at a temperature ofabout 1140 C. This phosphor has essentially the following composition,assuming no loss of Sb, C1 or B:

EXAMPLE 20 Relative mols: Grams 6.00-CaHPO; 828 3.0042100, 288 0.80-H B0s0 0.10-57303 29 0.50-CaCl 1 50 1 CaCOs+81 NHACL The above ingredientswere mixed and fired in the same manner as in Example 19 and had thefollowing composition, assuming no loss of Sb, C1 or B:

9. IOCaO 3P O 0.4013 0 '0.2SbOCl- 0.40CaCl,

EXAMPLE 21 Relative mols: Grams 6.-00--CaHPO 828 3.12--CaCO 312 1.10-HBO 68 0.10Sb,0 29 0. 64CaCl 1 64 1 CaCOs+104 NH4C1.

The above ingredients were mixed and fired in the same manner as inExample 19 and had the following composition, assuming no loss of Sb, C1or B:

The above ingredients were mixed and fired in the same manner as inExample 19 and had the following composition, assuming no loss of Sb, C1or B:

9.22CaO 3P O -0.25'B O 0.2SbOCl- 0.54CaCl EXAMPLE 23 Relative mols:Grams 6.00-CaHPO, 828 3.12CaC0 3 12 1.IOH BO 68 0.10Sb O 29 0.36CaCl- 136 1 CaSOs+58 NHICI.

The above ingredients were mixed and fired in the same manner as inExample 19 and had the following composition, assuming no loss of Sb, C1or B:

9.22Ca0 3?;05 0.5 5B O 0.2SbOCl 0.26CaCl EXAMPLE 24 Relative mols: Gramseoo-canPo, 828 3. l2--'CaCO 3 12 0.5OH BO 31 0.10Sb O 29 0.36'CaCl 1 361 oac03+104 Nnlcl.

The above ingredients were mixed and fired in the same manner as inExample 19 and had the following composition, assuming no loss of Sb, C1or B:

9.22CaO' 31 0 0.25Bg0; 0.2SbOCl- 0.26CaCl,

9 EXAMPLE 25 Relative mols: Grams 6.00CaHPO 828 2.88CaC 288 1-10'"H3BO3v 0.10Sb O 29 0.64-CaC1 1 64 1 CaCOa+104 NHr'Cl.

The above ingredients were mixed and fired in the same manner as inExample 19* and had the following composition, assuming no loss of Sb,C1 or B:

8.98Ca0 3P O 055E 0 0.2'SbOCl 0.54CaC1 EXAMPLE 26 Relative mols: Grams6.00CaHPO n t 828 2.88CaCO 2 85 0.50H BO 31 0.10Sb O 29 0.64CaCl 1 64 1CaCOzx+104 NHeCl.

The above ingredients were mixed and fired in the same manner as inExample 19 and had the (following composition, assuming no loss of Sb,C1 or B:

8.98CaO 3P O 025E 0 0.2-SbOCl 0.54CaCl EXAMPLE 27 Relative mols: Grams6.00-CaH-PO 828 2.88CaCO 288 14041 130 68 0.10-Sb O 29 0.36-CaCl 1 36 1CuCOs+ 58 NH4CI.

The above ingredients were mixed and fired in the same manner as inExample 19 and had the following composition, assuming no loss of Sb, C1or B:

As many widely different embodiments of this invention may be madewithout departing from the spirit and scope thereof, it is to beunderstood that this invention is not limited to the specificembodiments except as defined in the appended claims.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. A luminescent material consisting essentially of an alkaline earthhalogenated borapatite activated with antimony wherein the alkalineearth is predominately calcium.

2. A luminescent material according to claim 1 wherein minor amounts ofan element selected from the group consisting of strontium, barium andcadmium are partially substituted for calcium in the alkaline earthhalogenated borapatitc.

3. A luminescent material according to claim 1 having the formula:

xMO 3P O 1 3 0 wSbOX zMX wherein w=0.05 to 0.5

x=8.85 to 9.35

y=0.25 to 0.55

z=0.15 to 0.65

M is the alkaline earth metal and X is a halogen.

4. A luminescent material according to claim 3 wherein X is selectedfrom the group consisting of [fluorine and chlorine.

5. A luminescent material according to claim 3 having the followingformula:

xCaO 31 205 -yB O ZCELFZ wherein .x=8.85 to 9.35

y=0.25 to 0.55 Z=0.15 to 0.65

6. A luminescent material according to claim 5 having essentially thecomposition:

9.10CaO' 3P O 0.43 0 0.2SbOF 0.40CaF 7. A luminescent material accordingto claim 5 having essentially the composition:

8. A luminescent material according to claim 5 having essentially thecomposition:

8.85Ca0- 31 10 0.313 0 0.2SbOF- 0.65CaF 9. A luminescent materialaccording to claim 5 having essentially the composition:

-8.98CaO' 3P O 0.2513 0 0.2SbO1F 0.54CaF 10. A luminescent materialaccording to claim 5 having essentially the composition:

9.22Ca0- 3P O O.55B O 0.2SbOF- 0.54CaF 11. A luminescent materialaccording to claim 5 having essentially the composition:

8.85CaO- 3P O 0.33 0 0.2SbOtF- 0.15CaF 12. A luminescent materialaccording to claim 5 having essentially the composition:

13. A luminescent material according to claim 5 having essentially thecomposition:

9.35'Ca0-3P O -0.3B O -0.2SbOF-O.15CaF 14. A luminescent materialaccording to claim 3 having the formula:

xCaO- 3P O -yB O -0.2Sb0C1' zCaCl wherein x=8.92 to 9.22 y=0.25 to 0.55z=0.26 to 0.54

15. A luminescent material according to claim 14 having essentially thecomposition:

8.92Ca0- 3P 0 0.45 B 0 0.2SbOCl 0.5CaCl 16. A luminescent materialaccording to claim 14 having essentially the composition:

8.98Ca0 3P O 0.25 B 0 0.2SbOCl 0.26CaCl 17. .A luminescent materialaccording to claim 14 having essentially the composition:

9.10Ca0- 3P O 0.40B O 0.2SbOCl 0.40CaCl 18. A luminescent materialaccording to claim 14 having essentially the composition:

8.98Ca0 3PQO 055E 0 0.2SbOCl 0.54CaCl 11 12 19. A luminescent materialaccording to claim 14 hav- References Cited ing essentially thCcomposition: UNITED STATES PATENTS H 5- z 3- 2 2,488,733 11/1949 McKeaget a1. 2s2, 301.4 P

20. A luminescent material according to claim 14 hav- 5 3,143,510 3/1964wanmaker 252301-4 mg Senuauy ROBERT D. EDMONDS, Primary Examiner8.98Ca0-3P O -0.55B 0 -0.2SbOCl-O.26CaCl

